Jig assembly for implantation of a fracture fixation device

ABSTRACT

A jig assembly includes a jig having an elevated first portion having holes or slots to align a drill with screw holes in an intramedullary portion of a fixation device, and a lower second portion having openings in axial alignment with holes on a plate portion of the fixation device. The jig may be locked relative to the fixation device. The jig assembly further includes one or more of sleeves, drill guides and gauges for facilitating the drilling of appropriate holes into bone both beneath and above the fixation device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to surgical devices. More particularly,this invention relates to tools for implanting fracture fixationdevices.

2. State of the Art

Severe long bone fractures are often treated with plating. In plating, arelatively large incision is made at the location of the fracture,musculature and tendons are displaced from the bone to expose the bonesurface, and a bone plate is fixedly attached to one or more pieces ofthe fractured bone in a manner which, ideally, supports and stabilizesthe fracture for healing. Due to the relatively invasive nature of theprocedure required to implant the plate, plating is generally reservedfor fractures which cannot be treated with a less invasive method ofimmobilization.

Less complicated fractures are often treated with casting or wires.However, such conservative treatment may not provide the stabilizationand support necessary for desirable recovery. Yet, the operativeprocedure of plating is often too invasive for the relative non-severityof the fracture. Moreover, conventional plating can result in tendonirritation and skin necrosis, and may require extensive periostealstripping in order to apply the plate on the bone surface. As such, manyof the less displaced fractures, and particularly metaphyseal fractures(fractures at the end of the long bones), remain undertreated.

By way of example, a Colles' fracture, which results from compressiveforces being placed on the distal radius bone, and which causes backwarddisplacement of the distal fragment and radial deviation of the hand atthe wrist, is treated with a dorsal plate when there is a significantdegree of displacement. However, a less-displaced Colles' fracture iscommonly undertreated due to the hesitancy of physicians to prescribeoperative and invasive treatment. If not properly treated, such afracture results in permanent wrist deformity. It is therefore importantto align the fracture and fixate the bones relative to each other sothat proper healing may occur.

More recently, minimally invasive fixation devices have become availablefor treatment of wrist fractures. Particular devices, such as thatdescribed in co-owned and co-pending U.S. Ser. No. 10/159,611, filed May30, 2002, and Ser. No. 10/315,787, filed Dec. 10, 2002, include anintramedullary portion which is secured within or to the cortical bonewith cross-fastened screws. In addition, these fixation devices includea plate portion into which a plurality of bone pegs are secured. Pegs ofan appropriate length are oriented in relatively oblique angles relativeto each other to stabilize the subchondral bone fragments relative tothe plate portion.

It is therefore necessary to provide to the surgeon a tool facilitatinglongitudinally displaced holes drilled through the cortical bone inalignment with the longitudinally displaced screw holes in theintramedullary portion of the fixation device so that the fasteningscrews may be inserted through the bone and the screw holes. Inaddition, it is also preferable to provide tools which are adapted todrill holes into the subchondral bone for the pegs in the desiredoblique directions. In addition, tool must be provided for selectingpegs of an appropriate length.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a jig assembly forassistance in implantation of a fixation device relative to a fracturedbone.

It is another object of the invention to provide a jig assembly for afixation device designed to treat metaphyseal fractures.

It is a further object of the invention to provide a jig assembly whichprovides proper alignment between longitudinally displaced holes drilledin bone and corresponding openings in an intramedullary portion of thefixation device such that fasteners can be inserted through the holesand openings.

It is an additional object of the invention to provide a jig assemblywhich facilitates drilling of axially aligned holes through peg holes ina plate of a fixation device and through metaphyseal bone.

It is yet another object of the invention to provide a jig assemblywhich properly and easily measures drilled hole depth.

It is also an object of the invention to provide a jig assembly whichprevents potential tissue damage by the drill.

It is yet another object of the invention to provide a jig assemblywhich stops the drill at a precise distance relative to a jig so that animplant within the bone below is not damaged, even though the radiusbone into which the implant is positioned may have a varying thicknessalong its length and different thicknesses in different patients.

It is also an object of the invention to provide a depth gauge for a jigassembly which easily and accurately determines the length of pegs whichshould be used with the fixation device.

In accord with these objects, which will be discussed in detail below, ajig assembly for a fixation device is provided.

In order to more easily understand the jig assembly, it is helpful tounderstand that the jig assembly is adapted for use with an orthopedicimplant such as the fixation devices described in detail in U.S. Ser.No. 10/159,611, filed May 30, 2002, and Ser. No. 10/315,787, filed Dec.10, 2002, which are hereby incorporated by reference herein in theirentireties. In brief, such fixation devices include a proximalintramedullary nail portion and a distal supra-metaphyseal plate portionwhich is horizontally and vertically offset relative to the nail portionby a neck portion. The nail portion includes two or more threaded screwholes, and the plate portion has a low, narrow profile and includesthree longitudinally displaced peg holes, each of which is adapted toorient a peg in a different orientation from the others. The plateand/or neck portions also include a threaded locking hole.

With the fixation devices in mind, the jig assembly includes a jighaving an elevated first portion in alignment over the screw holes ofthe intramedullary portion of the fixation device, and a second portionseatable on the plate portion of the fixation device. The first portionincludes longitudinally displaced holes or slots, as described furtherbelow, to longitudinally align a drill with the screw holes in theintramedullary portion of the fixation device. The second portionincludes openings in axial alignment with the peg holes. The jig alsoincludes a hole over the threaded locking hole in the fixation device,and the assembly includes a locking screw adapted to extend through thehole and couple the jig to the fixation device at the threaded lockinghole.

According to one embodiment of the invention, the first portion of thejig includes a plurality of longitudinally displaced holes, a firstsleeve adapted to be received in any of the holes, and a second sleevesized to be received within the first sleeve, but removable therefrom.The second sleeve is diametrically sized to guide a rotary drill to cutthe bone cortex, and the first sleeve is diametrically sized to receivethe head and body of a cortical screw adapted to engage within the screwholes of the intramedullary portion of the fixation device. Thesleeve-in-sleeve structure may be positioned in each of the holes of thefirst portion of the jig to guide the drill for each of the corticalscrew holes.

According to another embodiment of the invention, the first portion ofthe jig includes a plurality of longitudinally displaced holes, andslots which provide lateral entrance into each of the holes. A drill maybe side loaded into holes via the slots. A bridged-sleeve is optionallyprovided for use with the holes, and (1) accounts for changing ordifferent thicknesses in the bone (2) more stably guides the drill, and(3) prevents the drill from catching and tearing tissue near theentrance to the drilled cortical bone.

The jig assembly further includes a drill guide having a threaded endwhich is positionable within the openings in the second portion of thejig and threadably engageable within the peg holes. A single drill guidemay be moved from one peg hole to the next to drill the required holes.The drill guide preferably includes a depth gauge for measuring thedepth of a drilled hole and determining an appropriate size of bone pegfor use with the fixation device.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a jig assembly and fracturefixation system according to the invention;

FIG. 2 is a side elevation view of a locking screw of the jig assemblyof the invention;

FIG. 3 is a side elevation view of a drill guide of the jig assembly ofthe invention;

FIG. 4 is a longitudinal section view of the drill guide of FIG. 3;

FIG. 5 is a perspective view of another embodiment of a jig assemblyaccording to the invention coupled to another embodiment of a fracturefixation system;

FIG. 6 is an inverse perspective view of the jig of the jig assembly ofFIG. 5;

FIG. 7 is a first side perspective view of a further embodiment of a jigassembly and fracture fixation system according to the invention;

FIG. 8 is a second side perspective view of the jig assembly andfracture fixation system shown in FIG. 7;

FIG. 9 is a perspective view of a guide sleeve according to theinvention;

FIG. 10 is a longitudinal section view of the guide sleeve of FIG. 9;

FIG. 11 is a side elevation of the jig coupled to an implant, with abridged sleeve guiding a drill bit into a relatively thick radius bone;

FIG. 12 is a longitudinal section view of the same elements shown inFIG. 11;

FIG. 13 is a longitudinal section view similar to FIG. 12 but where theradius bone is relatively thinner;

FIG. 14 is a perspective view of another embodiment of a drill guideaccording to the invention, with a view 180° about the drill guideappearing the same;

FIG. 15 is a side elevation of a gauge according to invention;

FIG. 16 is a side elevation of the gauge according to the invention,rotated 90° relative to FIG. 15; and

FIG. 17 is a view similar to FIG. 16 of an alternate embodiment of thegauge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accord with these objects, which will be discussed in detail below, ajig assembly 100 for a fracture fixation device 10 is shown.

In order to provide context for the features and use of the jig assembly100, it is helpful to first understand the type of fracture fixationdevices for which the jig assembly is intended. Similar fracturefixation devices 10 are described in detail in U.S. Ser. No. 10/159,611,filed May 30, 2002, and Ser. No. 10/315,787, filed Dec. 10, 2002, whichare hereby incorporated by reference herein in their entireties. Inbrief, the fixation device 10, which is slightly modified from thedevices described in the incorporated specifications and may includeinventive features relative thereto, includes a proximal intramedullarynail portion 12 and a distal supra-metaphyseal plate portion 14 which ishorizontally and vertically offset relative to the nail portion by aneck portion 16. The neck portion 16 may include a notch 18 tofacilitate coupling of the jig assembly 100, as described in more detailbelow. The nail portion 12 includes a relatively rigid section 20provided with two or more threaded screw holes 22, 24 for corticalscrews 26, 28, a tapered section 30, and a relatively stiff, but lessrigid end section 32 formed with a curve 34 to facilitate entry into themedullary canal of a bone, e.g., the radius bone. The plate portion 14has a low, narrow profile, preferably with a convex upper surface 36 anda concave undersurface 38, and includes three longitudinally displacedpeg holes 40, 42, 44, each of which is adapted to orient a peg, e.g.,peg 46, in a different orientation from the others. The plate and/orneck portions 14, 16 also include a threaded locking hole 48.

With the fixation device 10 in mind, the jig assembly 100 includes a jig102 having an elevated first portion 104 in alignment over the rigidportion 20 of the intramedullary nail portion 12 of the fixation device10, and a second portion 106 having a concave lower surface 108 which isstably seatable on the upper convex surface 36 of the plate portion 14of the fixation device 10. The first portion 104 includes longitudinallydisplaced guide holes 110, 112 aligned with the screw holes 22, 24 ofthe fixation device 10. The second portion 106 includes openings 114,116 (and another not shown) which provide access to peg holes 40, 42,44. The jig 102 also includes a hole 118 in alignment with the threadedlocking hole 48 of the fixation device 10.

A locking screw 120 extends through the hole 118 and couples the jig 102to the fixation device 10. More particularly, referring to FIG. 2, thelocking screw 120 includes a shaft 122 having a threaded end 124 sizedto engage the locking hole 48 and a handle 126 at an opposite endthereof for manually rotating the locking screw into engagement. Thelocking screw 120 preferably also includes a hex or square driveropening 128 for mechanically rotating the locking screw 120 to lock thejig 102 relative to the fixation device 10.

Referring back to FIG. 1, the jig assembly 100 further includes asleeved drill guide 130 comprising an outer first sleeve 132 adapted tobe received in any of guide the holes 110, 112, and an inner secondsleeve 134 sized to be received within the first sleeve 132, butremovable therefrom. The second sleeve 134 includes a handle 136 formanual insertion and removal into the guide holes 110, 112, and a bore137 diametrically sized to guide a rotary drill to cut the bone cortex.The first sleeve includes a handle 138 for manual insertion into andremoval from the second sleeve, and a bore 140 diametrically sized toreceive the head and body of the cortical screws 26, 28 which areadapted to engage within the screw holes 22, 24 of the intramedullaryportion of the fixation device 10.

Referring to FIGS. 1, 3 and 4, the jig assembly 100 further includes adrill guide 150 having a threaded end 152 which is positionable withinthe openings 114, 116 in the second portion 106 of the jig 102 andthreadably engageable within the peg holes 40, 42, 44. The drill guide150 preferably includes a stepped bore 154 having a larger diameterupper portion 156 and a smaller diameter lower portion 158. The lowerportion 158 accommodates a drill bit appropriately sized for drilling ahole into bone for a peg 46, while the upper portion 156 accommodates amovable scale of a prior art depth gauge (not shown) for measuring thedepth of a drilled hole and determining the location and depth of thedrilled hole relative to particular anatomical structure. The drillguide 150 may be moved from one peg hole to the next to drill therequired holes.

Turning now to FIG. 5, a second embodiment of a jig assembly 200 isshown. An upper first portion 204 of the jig 202 of the assembly 200includes a plurality of longitudinally displaced circular holes 210,212, 214, and slots 216, 218, 220 which provide lateral entrance intoeach of the holes. The slots 216, 218, 220 are preferably non-radial,and more preferably oriented parallel to both a radius and a tangent ofthe respective holes. A drill bit 260 may be side loaded into the holes210, 212, 214 via the slots 216, 218, 220, without the use of a sleeve.The handle alone guides the bit, and the location of the slots relativeto the holes operates to facilitate retention of the drill bit when thebit is rotated in a counterclockwise direction. This construction speedsuse of the jig, as the drill bit 260 may be rapidly moved into and outof holes 210, 212, 214. After the holes are drilled into the bone, adriver (not shown) for the screws 26, 28 (FIG. 1) likewise can beinserted into the 210, 212, 214, with the screws manually positionedbeneath the jig 202 and engaged by the driver.

Referring to FIG. 6, in the lower portion 206 of the jig 202, twoopposite side openings (recesses) 214, 215 are provided which provideaccess to peg holes 40, 42 (see FIG. 1) in the fixation device 10 atherebeneath, and a relatively distal bounded opening (hole) 216 isprovided for access to a distal peg hole 44 (also in FIG. 1). The sideopenings are preferably symmetrical so that the jig 202 may be used withboth left and right hand fixation devices 10 a, as the left and righthand models will have oppositely directed pegs in corresponding pegholes 40, 42. In FIG. 5, drill guides 150 are shown coupled in each ofthe peg holes, though a single drill guide may be used and moved betweenthe peg holes as holes are drilled in alignment with each. A hole 208 isalso provided for receiving a locking screw 120 to couple the jig 202 tothe fixation device 10 a. Fixation device 10 a and 10 (FIG. 1) aresubstantially the same with the exception that device 10 a includesthree cortical screw holes 22 a, 24 a, 25 a, and device 10 includes onlytwo such holes 22, 24.

Turning now to FIGS. 7 and 8, according to another embodiment of theinvention, the jig 202 is shown with a bridged-drill sleeve 300extending over the drill bit 260, and an alternate drill guide 302provided with a novel depth gauge 304. Referring specifically to FIGS. 9and 10, the bridged-drill sleeve 300 includes a tube 310 defining apassage 311, and an upper bearing 312 having a bore 313 coaxial with thepassage 311. A bridge 314, laterally displaced from the axes of the tube310 and the bearing 312, couples the tube 310 and bearing 312 in aspaced apart relationship.

Referring now to FIGS. 9 through 12, the bore 313 of the bearing 312 hasa relatively large first inner diameter sized to receive a proximalshoulder portion 262 of the drill bit 260. The passage 311 has a secondinner diameter sized to stably receive and guide a relatively smallerdistal portion 263 of the drill bit 260.

The shoulder portion 262 of the bit 260 is too large to fit through thecircular holes 210, 212, 214 in the upper first portion 204 of the jig202, and thus when the bit 260 is advanced through the jig, the shoulderportion 262 will abut the top surface of the first portion 204 of thejig 202 and stop the drill tip 264 at a predetermined distance relativeto the jig 202, regardless of the thickness of the radius bone 400.

The bridge 314 is sized to be at least partially received within a slot216, 218, 220 of the jig 202 (see FIG. 8) and the tube 310 is sized tobe received within a hole 210, 212, 214. In order to guide the bit 260to drill through different thicknesses of the radius bone (either avarying thickness of one bone beneath the holes 210, 212, 214 or inradius bones of various patients), the tube 310 and bridge 314 may slideup and down through a respective hole and slot relative to the jig.Based upon the thickness of the radius bone 400 on which the bottom 318of tube 310 is positioned, the top end 316 of the tube 310 and bridge314 will be located at a variable vertical location relative to the jig202 while still operating to stably guide the drill bit 260 toward ahole 22 a, 24 a, 25 a in the implant 10 a. For example, compare thelocation of the top end 316 and bottom end 318 of the tube 310 in FIGS.11 and 12, where the implant 10 a is positioned within a radius bone 400having a relatively thicker cortex, to the location of the top end 316and bottom end 318 of the tube 310 in FIG. 13 where the implant 10 a ispositioned within a radius bone 400 a having a relatively thinnercortex. Thus, the jig 202 with bridged sleeve 300 stably guides thedrill bit toward screw holes in an implant regardless of the thicknessof the radius bone.

The sleeve also has other advantages. The relatively massive size of thebearing 312 improves stability of the guide. The placement of a portionof the bridge 314 within a slot 216, 218, 220 of the jig 202 preventsthe guide 300 from rotating relative to the jig when the drill bit 260is rotated. Further, the bottom end 318 of the tube 310 when positionedon the radius bone 400 prevents the drill tip 264 from catching andtearing non-bone tissue near the entrance to the drilled cortical bone.

Referring to FIG. 14, the drill guide 302 includes a threaded end 320for threaded engagement with a peg hole of the fixation device 10 a, anda relatively constant diameter bore 322. A window 324, open to the bore322, is defined on each of two diametrically opposite sides of the drillguide 302. Graduated indicia 326 corresponding to a scale is providedalong the sides of the windows 324. In a preferred embodiment, theindicia 326 correspond to millimeters and more particularly providegraduated indications of a depth of 14 mm to 30 mm, as measured relativeto the tip 334 of a gauge 304 (FIGS. 15 and 16).

Referring to FIGS. 15 and 16, the gauge 304 includes a handle portion326, a shaft 328 insertable through the bore 322 and having a referencemark 330 thereon, and an end portion 332. The reference mark 330 isclearly identifiable and preferably engraved or etched on the shaft 328,though it may also be applied or provided through other means such as,e.g., paint, oxidation, enamel, or a raised ridge or other mark.

The end portion 332 of the gauge is slightly angled relative to theremainder of the shaft 328, e.g., by approximately 3° to 6°, and mostpreferably 4.3°. The end portion 332 is spring-like in that if it isradially deformed from its pre-set angle relative to the shaft 328 itwill return to the pre-set angle once the deformation force is removed.The end portion 332 includes a rounded tip 334 which ensures that thegauge rides smoothly in and out of drilled bone and bore 322 of thedrill guide, and an angled upper catch 336, preferably angled atapproximately 105° relative to a longitudinal axis through the endportion 332. The angle of the upper catch allows a user to retrieve thegauge without chipping bone, which may occur with a prior art gaugehaving a right-angle ledge. The end portion 332 preferably also slightlytapers in a lateral direction. Where the gauge is intended for use inconjunction with fracture fixation implants designed for the distalradius, the end portion 332 preferably has a length betweenapproximately 10 mm and approximately 25 mm, and more preferablyapproximately 15 to 18 mm, and the diameter of the end portion ispreferably less than approximately 3 mm, and most preferablyapproximately 1.5 mm. Other dimensions may be provided where the gaugeis used in conjunction with orthopedic implants intended for other bonefractures.

When the drill guide 302 is coupled to a fixation device at a peg hole,the depth of a hole drilled therethrough may be measured by removing thedrill and inserting the gauge 304. The end portion 332 and shaft 328 ofthe gauge 304 are fed through the bore 322 such that the end portion 332is resiliently radially inwardly bent against the preformed angle by therelatively narrow diameter of the bore. Once the rounded tip 334 of thedrill guide exits the far end of the drilled hole, the end portion 332springs back such that the ledge 336 catches on the far cortex of thebone. The depth of the hole (or size or length of an appropriate sizebone peg) is measured (or otherwise determined) by the location of thereference mark 330, which is viewed through the window 324, relative tothe indicia 326 on the drill guide 302. The measurement determines thesize of the peg which will be inserted into the peg hole. Aftermeasurement, the gauge 304 is withdrawn from the drill guide 302. Duringwithdrawal, the obliquely angled catch easily releases from the bone andthe rounded tip 334 advantageously does not drag or scrape through thedrilled hole. The process is repeated for each bone peg hole.

Referring to FIG. 17, additionally or alternatively, the gauge 304 a maybe provided with graduated indicia 326 a corresponding to a scale (andmay or may not include the reference mark 330 a) so as to also be usedwith a conventional drill guide which does not have a window while stillproviding the advantages of gauge 304. In such case, the measurement ofthe drilled hole is read by referencing the top of the conventionaldrill guide against the scale provided by the indicia 326.

There have been described and illustrated herein embodiments of a jigassembly for implantation of a fixation device. While particularembodiments of the invention have been described, it is not intendedthat the invention be limited thereto, as it is intended that theinvention be as broad in scope as the art will allow and that thespecification be read likewise. Thus, while particular dimensions andangles have been disclosed, it will be appreciated that other dimensionsmay be used as well. In addition, elements of one embodiment may becombined with elements of another embodiment. For example, and not byway of limitation, the drill guide 302 may be used in place of drillguide 150 in all embodiments. It will therefore be appreciated by thoseskilled in the art that yet other modifications could be made to theprovided invention without deviating from its spirit and scope asclaimed.

1. A jig assembly for use in implantation of an orthopedic implant,comprising: a) a jig including a first portion provided with a pluralityof longitudinally displaced holes, and a second portion provided with aplurality of openings, and a plurality of lateral slots extending intosaid longitudinally displaced holes through which a drill bit can belaterally entered into said holes, said second portion being verticallydisplaced relative to said first portion; b) a drill guide receivablewithin each of said plurality of openings of said second portion of saidjig; c) gauge means for measuring a depth of a hole drilled into bonethrough said drill guide; and d) locking means for locking said jigrelative to an orthopedic implant.
 2. A jig assembly according to claim1, wherein: said slots are non-radially oriented relative to said holes.3. A jig assembly according to claim 1, wherein: when said locking meanslocks said jig relative to the orthopedic implant, said first portion ofsaid jig extends parallel to a portion of the implant extending beneathsaid first portion.
 4. A jig assembly according to claim 1, wherein:said plurality of openings in said second portion are longitudinallydisplaced.
 5. A jig assembly according to claim 1, wherein: saidplurality of openings in said second portion includes two laterallydisplaced recesses.
 6. A jig assembly according to claim 5, wherein:said plurality of openings in said second portion includes a boundedopening.
 7. A jig assembly according to claim 1, wherein: said secondportion of said jig includes a concave undersurface.
 8. A jig assemblyaccording to claim 1, wherein: said gauge means measures said depth ofsaid hole relative to an anatomical structure.
 9. A jig assemblyaccording to claim 1, wherein: said drill guide includes a bore, awindow in a side of said drill guide open to said bore, and graduatedindicia provided along at least one side of said window, and said gaugemeans includes a shaft insertable into said bore and provided with areference mark thereon.
 10. A jig assembly according to claim 9,wherein: said shaft has an end portion angled relative to an adjacentportion thereof, and said end portion includes a rounded tip having anupper catch, wherein said end portion may be resiliently bent relativeto said adjacent portion.
 11. A jig assembly according to claim 1,further comprising: f) a drill sleeve including a tube defining alongitudinal passage, an upper bearing having a bore coaxial with saidpassage, and a bridge portion laterally displaced from the axes of saidtube and said bearing which couples said tube and said bearing in aspaced apart relationship.
 12. A jig assembly according to claim 11,wherein: said passage has a smaller diameter than said bore.
 13. A jigassembly according to claim 12, wherein: said bridge portion is sized tobe slidably moved within each of said slots.
 14. A jig assemblyaccording to claim 1, wherein: said drill guide is threadably engageablein each of said plurality of openings of said second portion of saidjig.
 15. A jig assembly for use during implantation of an orthopedicimplant at least partially into a medullary canal of cortical bone,comprising: a) a rigid member removably couplable relative to theimplant, said rigid member provided with an opening and an uppersurface; b) a guide longitudinally movable within said opening relativeto said rigid member, said guide including a distal tubular portionhaving a distal end and a length which does not extend higher than saidupper surface of said rigid member when said distal end is positioned onthe cortical bone, and a proximal tubular portion coaxial with saiddistal tubular portion, said distal and proximal tubular portions beingin a spaced apart relationship; and c) a drill bit including a proximalportion and a relatively distal portion, said distal portion having asmaller diameter than a diameter of said proximal portion; wherein saiddiameter of said distal portion is sized to fit through said opening andsaid guide, and said diameter of said proximal portion is sized tofunction as a stop against said upper surface of said rigid member. 16.A jig assembly according to claim 15, wherein: said guide is slidablymovable relative to said rigid member.
 17. A jig assembly according toclaim 15, wherein: said guide further includes a bridge portion whichrigidly couples said proximal and distal tubular portions of said guidein said spaced apart relationship, said bridge portion being laterallyoffset relative to a longitudinal axis extending through said proximaland distal tubular portions.
 18. A jig assembly according to claim 15,wherein: said proximal tubular portion has an inner diameter sized toreceive said proximal and distal portions of said drill bit, and saiddistal tubular portion has an inner diameter which is larger in diameterthan said distal portion of said drill bit but smaller in diameter thansaid proximal portion of said drill bit.
 19. A jig assembly according toclaim 15, wherein: said proximal tubular portion of said guide issubstantially more massive than said distal tubular portion of saidguide.
 20. A jig assembly according to claim 15, further comprising:means for preventing said guide from rotating relative to said rigidmember when said drill bit is rotated.
 21. An orthopedic implant system,comprising: a) an orthopedic implant including an intramedullary portionand a plate portion longitudinally and vertically offset relative tosaid intramedullary portion; b) a jig including a first portion providedwith a plurality of longitudinally displaced holes and a second portionprovided with a plurality of openings, said second portion beingvertically displaced relative to said first portion; and c) means forcoupling said jig to said implant; wherein when said jig is coupled tosaid implant, said second portion of said jig is seated on said plateportion of said implant and said first portion of said jig is parallelto but vertically offset from said intramedullary portion of saidimplant; wherein said jig facilitates drilling holes into bone abovesaid intramedullary portion and beneath said plate portion.
 22. A systemaccording to claim 21, wherein: said plate portion has a convex surfaceand said second portion has a concave surface, said convex and concavesurfaces having corresponding curvatures.